Sash-balance



A. JOHNSON.

SASH BALANCE.

(No Model.)

No. 433,596. Patented Aug. 5, 1890.

WWW

UNITED STATES PATENT OFFICE.

AXEL JOHNSON, OF OAKLAND, ASSIGNOR TO THE MARSHALL IMPROVED VVINDOIVFURNITURE COMPANY, OF SAN FRANCISCO, CALIFORNIA.

SASH-BALANCE.

SPECIFICATION forming part of Letters Patent No. 433,596, dated August5, 1890.

Application filed March 26, 1890. Serial No. 345,342. (No model.)

To all whom, it may concern.-

Be it known thatI, AXEL JOHNSON, a citizen of the United States,residing at Oakland, Alameda county, State of California, have inventedan Improvement in Sash-Balances; and I do hereby declare the followingto be a full, clear, and exact description of the same.

.My invention relates to sash-balances and to that class of springstherein used known as spiral and it consists in a spiral spring returnedupon itself, so as to form independent layers, the one within the other.

The general object of my invention is to provide for the maximumstrength or tension with the minimum length of spring and to betterequalize the power of the spring.

The particular use to which at present I intend to put my spring is itsemployment in that form of sash-balance set forth in Letters Patent ofthe United States, No. 420325, issued to Benjamin Marshall January 28,1890, to which said patent reference is hereby made for a betterunderstanding of the utility of my invention.

Referring to the accompanying drawings for a more complete explanationof my invention, the figure is a section of a corner of a window-sash,showing my spring in elevation, its coils being here shown as distendedmore than they would be in practice, in order to show their outward andreturn course.

My springA is made of any suitable material, of anyproper shape incross-section, and of suitable dimensions. The course is spirallyoutward from one end to the other; but instead of stopping at the outerend it turns back upon or within itself, being still directed spirally,and returns to the first end, where it may stop or be carried backagain, if desired. Thus there are formed independent layers, the onewithin the other.

I get a spring with the maximum tension and strength with the minimumlength, and its power is better distributed and equalized. For itsparticular use I intend to place it in a bore made in the sash-rail B.To the edge of the sash is secured a plate 0, with which, at 0, one endof the spring is connected. I11

this plate is journaled a short turn-rod D, and

to theinner end of this rod the other end of the spring is attached. Therod carries a pinion E, which meshes with a rack F, fixed to thewindow-casing. In operation, as the sash is moved to a closed positionthe spring is wound up, and so serves as a balance or an assistance inraising the sash. The particular advantage of my spring in this use isthat I need not have a very long spring. A shorter one is moreconvenient and can be better applied to the sash. If I used an ordinaryspi- 6o ral spring, it would have tobe a very long one,

in order to get the necessary power, and a very deep bore would have tobe made in the sash to receive it. It would also have a tenth ency tobend and kink; but my spring is short, and yet has the necessary power,and

it remains perfectly straight under any required tension. Another greatadvantage in this connection is that its power is better distributed andequalized, and itatfects the sash about equally in all positions.

I do not confine my invention to the particular use I have described, asit may be used in other connections and for other purposes.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. In a sash-balance or analogous device, an axially-moving rod and arack and pinion for operating the same,in combination with a torsionalspring returned within itself,having one of its ends secured to theaxially-moving rod and the other fixed to a non-rotary piece,substantially as herein described. 8 5 2. In a sash-balance or analogousdevice, the torsional spring herein described, consisting of a singlecoiled piece returned within itself, having one of its ends fixed to anonrotary bearing and the other secured to a piece that has a rotarymovement.

In witness whereof I have hereunto set my hand.

AXEL JOHNSON.

